CVE-2026-15709: Red Hat Enterprise Linux 10

High severity, CVSS 7.5. EPSS: 0.9% chance of exploitation in the next 30 days.

A flaw was found in libsoup's WebSocket implementation when using the permessage-deflate extension. The extension's decompression loop (inflate()) processes data in chunks without enforcing an upper boundary limit on the output buffer size. While libsoup limits the incoming compressed frame size via max_incoming_payload_size, it fails to track or limit memory allocation during decompression. A separate check for decompressed size (max_total_message_size) exists but executes only after inflation is complete, and it is entirely disabled by default for client connections. A remote, unauthenticated attacker can exploit this by sending a small, highly compressed payload (a decompression bomb), causing unbounded memory allocation that triggers an Out-of-Memory (OOM) crash and a Denial of Service (DoS).

Affected products

  • Red Hat Red Hat Enterprise Linux 10: before 0:3.6.5-3.el10_2.14 (fixed in 0:3.6.5-3.el10_2.14)
  • Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support: before 0:3.6.5-3.el10_0.17 (fixed in 0:3.6.5-3.el10_0.17)
  • Red Hat Red Hat Enterprise Linux 6
  • Red Hat Red Hat Enterprise Linux 7
  • Red Hat Red Hat Enterprise Linux 8
  • Red Hat Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support: before 0:2.62.3-2.el8_4.10 (fixed in 0:2.62.3-2.el8_4.10)
  • Red Hat Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On: before 0:2.62.3-2.el8_4.10 (fixed in 0:2.62.3-2.el8_4.10)
  • Red Hat Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support: before 0:2.62.3-2.el8_6.10 (fixed in 0:2.62.3-2.el8_6.10)
  • Red Hat Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On: before 0:2.62.3-2.el8_6.10 (fixed in 0:2.62.3-2.el8_6.10)
  • Red Hat Red Hat Enterprise Linux 8.8 Telecommunications Update Service: before 0:2.62.3-3.el8_8.11 (fixed in 0:2.62.3-3.el8_8.11)
  • Red Hat Red Hat Enterprise Linux 8.8 Update Services For SAP Solutions: before 0:2.62.3-3.el8_8.11 (fixed in 0:2.62.3-3.el8_8.11)
  • Red Hat Red Hat Enterprise Linux 9: before 0:2.72.0-16.el9_8.3 (fixed in 0:2.72.0-16.el9_8.3)
  • Red Hat Red Hat Enterprise Linux 9.2 Update Services For SAP Solutions: before 0:2.72.0-8.el9_2.13 (fixed in 0:2.72.0-8.el9_2.13)
  • Red Hat Red Hat Enterprise Linux 9.4 Update Services For SAP Solutions: before 0:2.72.0-8.el9_4.12 (fixed in 0:2.72.0-8.el9_4.12)
  • Red Hat Red Hat Enterprise Linux 9.6 Extended Update Support: before 0:2.72.0-10.el9_6.9 (fixed in 0:2.72.0-10.el9_6.9)

Published 2026-07-14. Last modified 2026-09-24.